Mechanical movement.



No. 766,214. PATENTED AUG. 2, 1904.

A. w. BARR.

MECHANICAL MOVEMENT.

APPLICATION FILED FEB. 13, 1903.

N0 MODEL.

anti army newsrumlnumlu-smnt.

M'ran STATES Patented August 2, 1904- PATENT OFFICE.

MEGHANICAL MOVEMENT.

arcane}: forming part of letters Patent No. 766,214. dated August 2, 1904. Application filed February 13, 1903. Serial Ho. 143,167. In model.)

To all whom it may concern:

Be it hown that I, Azomsos W. BARR, a, citizenoft-heUnitedStates,residingatWorcester, in the county of \Vorcester and Commonweaith ofMassachusetts, have invented anew and useful Improvement in Mechanical Movements, of which the following is a speci fimtion accompanied by drawings forming a t of the same, in which Figure 1 represents a perspective view of the mechanical movement embodying my invention. Fig. 2 is a vertical central sectional View. Fig. 3 is a side view of the spirallyscored drum, the winding-drum having been removed- Fig. 4 is a perspective view of the spirallygrooved drum detached from the mechanism, and Fig. 5 is a side view of an electric car representing my mechanical movement attached thereto for the purpose of retracting the trolley whenever it is carried above the trolley-wiie-said Fig. 5 being designed to illustrate the nature of my invention and its principle of operation.

Similar figures of reference refer to similar parts in the difierent views.

The object of my present invention is to provide a mechanical movement by which a rotaryrnotion in one direction may be reversed at a predetermined point, and while said movement is applicable to a large variety of uses 1 have represented it in the accompanying drawings as applied to the purpose of retracting or lowering the trolley of an electric car whenever the trolley is carried above the line of the trolley-wire, as is the case when the trolley runs off the wire and is lifted by its spring, the object being to rewind the trolleyrope instantly and draw the trolley down out of the way of the guy-wires whenever the trolley leaps the trolley-wire.

Referring to Figs. 1 and 2 of the drawings,

which represent, respectively, perspective and sectional views of a mechanism embodying my present invention, 1 denotes a disk capable of being attached to anytixed framework as, for example. the dashboard :2 of an electric car in Fig. 5-and projecting from one side thereof a spindle 3, having one end reduced at am form a shoulder 5,and keyed to the reduced end 4 of the spindle is a disk-6, between which and the disk 1 is placed adrum 7, having one end open and'fitting a shoulder 8 on the inside of the disk .6, with the opposite end closed and provided with a hub 9, which is adapted to turn on the spindle 3. lnterposed between the disks'l and 6 and inclosing the drum 7 is a second cylindrical drum 10, upon which is wound one end of the trolley-cord 11, the opposite end being attached to the trolley-pole 12, pivoted in the usual manner upon a bracket 13 on the car 14 and carrying in its freeend a trolley-wheel 15 of the usual form of construction and adapted to run in contact with the trolley-wire 16 and being held against the trolley-wire by aspiral spring 17 as is usual in devices of this class. Inserted in the annular chamber 18, between the disk 1 and the closede nd of the drum 7. is a spiral spring 19, havingits opposite ends 20 and 21 attached to the drum T and the drum 10, respectively. so as to exert a slight torsional strain upon the drum 10 to wind up the trolley-cord 11 in order to take up any slack in the cord. The outer surface of the drum 7 is provided with a shallow spiral groove 22. and the inher surface of the drum 10 is provided with a longitudinal groove 23. Between the drums T and 10 and engaging both the spiral groove .22 and the longitudinal groove 23 is a steel ball 2i. so that the rotation of the drum 10 will carry the steel ball 2i in a spiral path around the drum 7, as determined by the groove 22, the drum Tbeing locked against rotation .by the latch-pin 25, held in an arm 26 and engaging one of the notches 27 in the open end of the drum 7. The drum 7 is held from rotating and against the torsional strain .of a spiral spring 28, coiled in the annular space within the drum 7, having one of its ends, 29, connected to the stationary disk 6-and its opposite end, 30. connected to the drum T, whereby the torsional strain of the spring '28 may be applied to rotate the drum 7 when the same is released by the withdrawal of the latch-pin 25. The withdrawal or unwinding of the 9 5 trolley-cord 11 serves to rotate the drum 10 in the direction of the arrow 31, Fig. 1, carrying the steel ball 2i along the spiral groove 22 in IElie directi nofthe' arrow 32, Fig. 4, If the trolley'icord -1 lfbe unwound su'liici'ently v to carry the steel ball 24 into the end 33 of the spiral groove, its further movement will rotate the drum 7 in the direction of the arrow 34 against the ten sionof the spiralspring 28, thereby removing 'thep'rssure of the drum 7 from the inner end of the latch-pin 25, which permits the latch-pin to be withdrawn from one of the notches 27 by the tension of a small blade-spring 35. The withdrawal of the latchpin permits the tension of the spring 28 to reverse the motion of the drum 7, and as the steel ball 24 is at that time at the end 33 of the spiral groove 22 the rotation of the drum 7 will also rotate the drum 10 in the direction of the arrow 36, Fig. 1, which will wind up the cord 11 around the drum 10. The withdrawal of the cord 11 will again wind up the spiral spring 28, and when the desired length of the cord has been unwound the drum 7 may be held from rotation by pushing the latchpin 25 intoone of the notches 27, when the pressure of the drum 7 against the pin will frictionally hold it from being removed by the tension of the blade-spring 35 until the continued movement of the cord 11 carries the steel ball '24 into the end 33 of the spiral groove 22, when the pressure of the drum 7 against the latch-pin will be again removed and the rotation ofthe drum 10 reversed to again wind up the cord ll. I

In the application of my mechanical movement to the trolley of an electric car the attendant will unwind enough of the cord 11 to enable the trolley-Wheel 15 to reach the trolley-wire 16, and he will then lock the drum 7 from rotation by the insertion of the latchpin 25. If, however, the trolley -wheel 15 should run off the wire 16, it would be carried up by the tension of the spring'l7 unwinding more of the cord 11 from the drum 10 until the steel ball 24 had reached the end 33 of the spiral groove 22, when the latch-pin 25 will be released, allowing the spiral spring 28 to wind up the cord 11 and draw the trolley-pole down into the position shown by broken lines 36, Fig. 5, thereby holding the trolley-pole down andclear of the guy-wires.

The application of a' device embodying my invention to the trolley of an electric car is herein made for the purpose only of showing its operation. If the cord 11 were to be drawn ofi for any other purpose, the contact of the steel ball with the end of the spiral groove would serve to release the latch-pin and allow the spiral spring to wind up the cord.

The gist of my invention consists in applying to the drum 10 or similar rotative element means for reversing the motion of the drum at a predetermined point, so that the drum may be free to turn in one direction until the predetermined limit of its movement has been reached, when its rotation will be instantly reversed, and the same result would also occur were the drums to be rotated other means than the'cord.

What I claim as my invention, and desire to secure by Letters Patent, is

1. In a mechanical movement, the combination with a drum'and a cord wound thereon, of a torsional spring applied to said drum to reverse its motion when the cord is unwound, to rewind the cord upon the drum, a second drum inclosed within said first mentioned drum, a second torsional spring applied to rotate said inclosed drum and normally held in a state of tension, a fixed disk at the end of said drums, a latch held by said disk and engaging said inclosed drum, an interposed member between said drums, capable of being rotated around said inclosed drum by the rotation of said outer drum, and meansfor engaging said inclosed drum at a predetermined point and imparting a movement thereto to release said latch, substantially as described.

2. In a mechanical movement, the combination of a fixed spindle, an inner drum held on said spindle and provided with a spiral groove, an outer inclosing drum having an interior longitudinal groove, a steel ball engaging said longitudinal and said spiral grooves, whereby the rotation of said outer drum will cause said ball to travel in a spiral path on said inner drum, means for imparting a limited rotative movement to said outer drum in opposite (11 7 rect1ons,a spring interposed between said fixed spindle and said inner drum-and normally.

applying a torsional strain to said inner drum, a latch forholding said inner drum andl restraining said spring, and means for withdrawing said latch when said ball reaches the end of its spiral path, whereby the tension of the released spring is made to rotate said inner and outer drums, substantially as described. y V

3. In a mechanical movement, the combination of a fixed spindle, a spirally,- grooved drum held on said spindle, an outer inclosing drum having a longitudinal groove, a'ballinterposed between said drums and engaging said grooves, a latch for locking the-spirallygrooved drum, a torsional spring applied to said locked drum to rotate it in one direction and means for withdrawing said latch at a predetermined point in the rotation of said outer drum, substantially as described. 5

4. In a mechanical movement, the combina: tion of a fixed spindle, an inner dr.u-m"7 and an outer drum 10 supported on said spindle, an external spiral groove in said inner drum, an internal longitudinal groove in said outer drum, and a steel ball interposed between said drums and engaging said grooves, whereby the motion of said outer drum is imparted tosaid inner drum when said ball, arrives atthe end of its spiral path, substantially as-described 5. In a mechanical movement. the combine tion ofa fixed spindle, a spirally-grooved l at a predeterinined point in the rotation of drum held on said spindle, an outer lnclosmg said outer drum, substantially as described. 10 drum having :1 longitudinal groove. a movable Dated this 7th day of February, 1903.

member interposed between said drums and I engaging said grooves, a latch for locking the ADDISON BARR spirally-grooved drum, :1 torslonal spring ap- Witnesses:

plied to said locked drum to rotate it 1n one RUFUS B. FOWLER,

direction and means for withdrmving said latch PEN ELOPE Com; ERBACII. 

